The present invention relates to a lock detecting connector which can detect that a pair of connectors engageable with each other are in a complete locked state.
Recently, automobiles carry air bags. Safety devices such as these air bags must be highly reliable, which thus demands that incomplete connection of male and female connectors be avoided with certainty. To meet such demand, connectors whose complete connection is detected electrically have been developed to date.
FIG. 1 shows a conventionally known lock detecting structure of this type. A groove-like engagement portion 1a is formed on the upper surface of a connector 1 on the male side that is firmly fixed on a board 2. On the other hand, a flexible lock piece having a projection 7a is integrally formed on the upper surface of a connector 5 on the female side to be engaged with the connector 1 on the male side, the projection 7a being held by the engagement portion 1a when both connectors 1, 5 are connected.
In addition, within the connector 1 on the male side, a pair of lock detecting electrodes 4a, 4b are disposed while positioned on both sides of an inverted T-shaped position determining piece 3 as shown in FIG. 2. On the other hand, within the connector 5 on the female side, a U-shaped short circuit electrode 6 is arranged so as to interpose the position determining piece 3 between the leg portions thereof as shown in FIG. 2.
In the thus designed lock detecting structure, as the connector 5 on the female side is being inserted into the connector 1 on the male side while elastically deforming a flexible lock piece 7 thereof, the short circuit electrode 6 is elastically deformed upward by a guide projection 3b formed on a partition wall 3a of the position determining piece 3 as shown in FIG. 3, so that the short circuit electrode 6 keeps distance from the detecting electrodes 4a, 4b at the initial stage of the insertion. Then, when the connector 5 on the female side has been inserted into a regular position of the connector 1 on the male side, the projection 7a of the flexible lock piece 7 is held by the engagement portion 1a to thereby unremovably lock both connectors 1, 5. At the same time, the short circuit electrode 6 comes out of the projection 3b to come in contact with the lock detecting electrodes 4a, 4b as shown in FIG. 4. The lock detecting electrodes 4a, 4b are connected to a not shown detecting circuit, so that it is judged that both connectors 1, 5 have been connected in the locked state by way of short-circuiting the lock detecting electrodes 4a, 4b.
In the aforementioned conventional lock detecting structure, the short circuit electrode 6 is disposed within the connector 5 on the female side. This structure is advantageous in preventing the detecting electrodes 4a, 4b from being short-circuited while insulated by foreign matter such as dirt and dust upon contact between the detecting electrodes 4a, 4b and the short circuit electrode 6, since foreign matter is hard to deposit on the short circuit electrode 6. However, this structure does not allow the user to check the condition of the short circuit electrode 6 visibly; i.e., the short circuit electrode 6 is left concealed, and this is undesirable in terms of quality control.
To overcome this problem, the short circuit electrode may be disposed on the outer surface of the connector, and a cover may be provided to cover the entire part of the connector having the short circuit electrode as long as the connector having the short circuit electrode is not connected to the mating connector. And the cover may be removed to expose the short circuit electrode when the short circuit electrode must be inspected visibly or when the connector having the short circuit electrode is connected to the mating connector. However, this design is still disadvantageous in involving an extra step of removing the cover prior to connecting both connectors, which leads to a reduction in the efficiency of the entire connecting operation.
An example of the connector using the above lock detection structure is shown in FIGS. 5 and 6.
FIG. 5 shows a connector housing 40 on the male side. A plurality of male terminals 41 are accommodated within the housing 40, and these terminals 41 project outward through the wall surface in the back of the housing 40. In addition, from the wall surface in the back projects a rib 42, which extends in parallel with the terminals 41 within the housing 40. A partition wall 43 standing upright in the middle of the rib 42 divides the upper surface of the rib 42 into right and left parts. Lock detecting terminals 44 are disposed on such right and left parts of the rib 42. Both lock detecting terminals 44 project outward through the wall surface in the back of the housing 40 like other terminals. On the other hand, a connector housing 45 on the female side accommodates a not particularly shown short circuit terminal. The short circuit terminal has such a shape as to come in contact with the lock detecting terminals 44 simultaneously upon engagement (complete engagement) of the connector housings 40, 45. Therefore, when both connector housings 40, 45 have been engaged with each other completely, both lock detecting terminals 44 are ready to conduct through the short circuit terminal. As a result, the complete engagement can be detected electrically.
However, the aforementioned structure in which the lock detecting terminals are disposed in the middle of the connector housing 40 addresses a problem shown in FIG. 7. The problem is that the edge portion of the connector housing 45 on the female side is caught on the distal end of the rib 43 or on the distal ends of the lock detecting terminals 44 when both housings 40, 45 are being engaged misaligned. This causes the rib and the like to be deformed, which may in turn make engagement of the connector housings or lock detection of the connector housings impossible depending on the degree of deformation.